Yugawaralite is a relatively rare calcium-rich zeolite often found as distinctive white to colorless bladed or tabular crystals. It typically forms in cavities within volcanic rocks and is prized by collectors for its attractive, often radiating crystal aggregates. First discovered near Yugawara Hot Springs in Japan, it is now found in various volcanic regions globally.
Is this yugawaralite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch yugawaralite with a known reference. Yugawaralite sits at Mohs 4.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Yugawaralite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Yugawaralite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellowish, pinkish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, bladed, radiating sprays.
Often confused with
Yugawaralite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside yugawaralite
Minerals reported to co-occur with yugawaralite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaAl₂Si₆O₁₆·4H₂O
- Mohs hardness
- 4.5
- Density
- 2.20 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Bladed, Radiating Sprays
- Cleavage
- Perfect On {010}
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Igneous Cavities in Volcanic Rocks and Hydrothermal Veins
- Typical price
- $20-150 for thumbnail to small cabinet specimens
Where rockhounds find yugawaralite
Classic worldwide localities
- Yugawara, Japan
- Iceland
- India
- USA (California)
- New Zealand
Field-hunting tip
Look in igneous cavities in volcanic rocks and hydrothermal veins country — that is the host setting where yugawaralite typically forms. If you start seeing quartz, calcite, prehnite in float, you are in the right ground. Field specimens usually show a tabular crystals, bladed, radiating sprays habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify yugawaralite?+
Where is yugawaralite found?+
How much is yugawaralite worth?+
What rocks look like yugawaralite?+
What minerals are found with yugawaralite?+
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Find yugawaralite on the map
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